Chuck



Patented .lune 21, 1932 UNITED STATES PAUL FORKARDT, OF DUSSELDORF, GERMANY cHUcK Application ined october s, 1929, serial No. 397,071, and in eefmany'Januey 21, November 30, 1931.

This invention relates to a so-called wedge chuck that is to say to a chuck in which the jaws are moved by means of wedge-shaped driving faces of a plunger centrally adjustable in the chuck. In known chucks of this kind, the engagement between the chuck jaws and the driving plunger has been eected by means of T-shaped slots with which engaged corresponding projections of the jaws or of the jaw holders. Owing to the T-shape of the slots, their exact manufacture as well as the changing of the jaws were rendered diliicult.

These drawbacks are eliminated according to the invention by the engagement between the driving plunger and the chuck jaws or jaw holders, being effected by means of clawshaped projections which are open at one side and engage with other like claws. These hookshaped projections, open at one side, can be easily and accurately machined, and more particularly they can be exactly ground by means of large grinding wheels.

The hook shape of the connection claws further enables the chuck jaws or the jaw t feet-ed either by hand or by means of a driving medium such as for instance compressed air or oil under pressure, as in other known chucks.

A construction of acchuck according to the invention is shown by way of example in the accompanying drawing.

Figure l is a cross section through the chuck in which the jaws are shown partly in elevation. The jaws are in engagement with a driving member.

Figure 2 is a longitudinal section through the chuck. y j

Fig. 3 is a view similar to Fig. l with the jaws out of engagement with the driving member.

slots.

`original jaws.

1929.- `Renewed VInthechuck'body 1,'the'jaws 2varel radially adjustable in the knowninanner in'Tishaped In the centre of the chuck bodyv 1s arranged a plungerV 3 whichcan be axially reciprocatedfby a rod 2. Y At the end ofthe plunger are'arranged in ajregular or irregular manner, claws Zjewhich7 as may be seen in Figure 3, are wedges inclined towards'the axis of the chuck. j The claws 4 engage claws n x 5 of the jaws 2, of the same-wedge angle as the claws 4;

By turning the plunger 3 about the axis of the chuck, the claws 4e and 5 can be brought into and out of engagement as shown in Figures l and 2. The point 7 of a` spring-controlled pin 6 engages kwith a recess 8 in the edge of the plunger., which is made so deep at one end that when the claws 4, 5 are in engagement, the pin Yspringsinto a seat Y and locks the plunger 'in the'engaged position. In the disengaged positiointhe pin is forced from its-seating, and projects beyond the surface-of the chuck, as shown in Figure 2, thereby indicating that the aws 2 and the piston 3 are disengaged. Spring-controlled pins 9 are used in the same way for locking thejaws 2 in the disengaged position., A square hole l0 in the r'ecessedfront face, is used for turning the plunger andi for throwing the jaws into and out of engagement, into which hole a turning key can be introduced. y

The working of the' chuck should be clear without any further description.

Y The I advantages of the chuck can be summed upin the following: a

1. The Vchuckcanbe easily cleaned without taking it topieces, after withdrawing the jaws.

2. In changing from one job to another, the jaws can be changed directly in a few seconds. It is, therefore, no longer necessary to use eXtra jaws which are screwed on the 3. In finishing the work blanks, it has been Y necessary hitherto each time to turn and toV grind again the jaws used, as the required ac-k curacy of the chucks was lost each time when taking them to pieces and itting up agam.

On the contrary, the chuck and the jaws ac- A" cording tothe invention can be made so accurately that the accurate jaws which are to be inserted for the finishing work, are held ready and can be used without any additional machining.

4. Owing to the easy interchangeability of the jaws, itis possible for the first time to use for small mass production Work mechanical chucks, more particularly compressed air or pressure oil chucks.

5. The simple wedge ixing has already made possible a particularly accurate Xing.

This advantage is still further increasedby-y the possibility of exact Vmachining of the claws 4 and`5.

What I claim is Y l. In a chuck, a body, jaws slidable radially fin `said body, a central driving plunger rotatable in saidbody, said jaws and said plunger having cooperating wedge shaped coupling kclaws open ratone side thereon, whereby rotation` of saidplunger will couple `and uncouple said chuck jaws to `and from said 2. -In av chuck,a body, jaws slidableradially .in said body,;a central driving plunger rotatable in said body, and cooperating wedge j means actuatedgby rotation of said plunger on said ,plunger and'on said jaws for coupling and uncoupling said jaws-to and from ysaid plunger.

L3. lIn a-chuck,;arbody,j aws slidable radially in said-tbody, a central driving plunger r0- .tatablein Said body, said jaws and said plungzerhaving cooperating wedge shaped coupling Clawsopen ,at 1one `side thereon, :whereby ro- -tation offsaid ,plunger will couple and un- ,couple said ,chuck jawsgto and `roin said plunger, and vspring-controlled means in said body for locking'said plunger in coupling positi'on.

'4. Infachuck, abody, jaws slidableradi ally .in -said body, va central Vdriving plunger rotatable 1in said body, said :jaws and said Aplunger having cooperating wedge shaped :cou lino' claws o en at one Yside Vthereon whereby rotation of said plunger will couple `and uncouplesaid chuck jaws to and from said plunger,s pring controlled means -i-n said .bodyforslockin saidplunger in coupling position, and sai jawsyin uncoupled position. v In testimonywhereofI'afiX my signature.

' v 'PA-UL FORKARDT. 

